1. Field of the Invention
The present invention relates to the structure of a multicolor ink ribbon for use with a dot impact printer.
2. Description of the Prior Art
In the past, various developments have been made with regard to a multicolor ribbon for a dot impact printer. For example, the invention disclosed in U.S. Pat. No. 4,526,487 is one of them. In this disclosure, a character or a picture image is formed in color by means of causing a printing head to strike individual colors or combinations of colors on a multicolor ink ribbon, provided with three color stripes of yellow, magenta, and cyan, or four color stripes of yellow, magenta, cyan and black, and which is contained in a cartridge equipped with a means to recirculate the ribbon.
However, the prior multicolor ink ribbon employed in a dot impact printer to perform color printing was made of a ribbon of single layer fabric in which three or four colors were impregnated in stripes, and therefore, the tip section of the printing head, or printing wire, would become soiled black due to the subtractive color mixture effects of the different inks which adhered to the tip or the wire when those colors were repeatedly printed. This was a particularly troublesome problem due to the fact that, when a printing wire in a soiled condition struck the yellow ink stripe, which was a bright color stripe, it badly soiled the yellow ink stripe of the ink ribbon so that the image created by repeated striking of the yellow ink stripe deteriorated.